The present invention relates generally to power meters and, more particularly, to an apparatus that provides energy usage and cost information regarding such energy usage for a single electrical device, such as an electrical appliance.
Single load electrical monitoring devices are designed to provide data regarding energy usage of a single electrical device, such an electrical appliance. Most such monitoring devices are typically referred to as power meters, but typically provide information on voltage and current, as well as power or wattage data regarding the electrical consumption of an electrical device. In addition to voltage, current, and wattage information, some power meters also provide cost information associated with the energy usage of the electrical device. These power meters allow a user to input per unit cost data associated with energy usage, such as a unit cost per kilowatt-hour, to the power meter and electronics within the power meter then determine and display a cost of operation of the electrical device based on the unit cost and the actual kilowatt usage of the electrical device.
Conventional single-load power meters are designed to be plugged into an electrical outlet, such as a wall outlet of a home, and have a socket into which the power cord of an electrical device is plugged. In this regard, the power meter includes a housing having a front side and a back side. The front side has a display for displaying energy usage and cost information and also has a socket for receiving the power plug of the electrical device. Prongs extend from the back side of the housing for plugging the power meter into the wall socket. Utility (or generator) power available at the wall socket may then be used to power the electrical device, and circuitry contained in the power meter monitors the power consumption to determine energy usage by the electrical device.
Since the prongs extend from the back side of the housing and the electrical device is plugged into the front side of the housing, there must be a line of sight to the general area of the wall socket to read the display of the power meter. This can be problematic when a power meter is used to measure the energy usage and display the cost of that usage for a large electrical device, such as a refrigerator, range, washer, dryer, or television, in which the sheer size of the electrical device obstructs a line of sight to the wall socket. To be used with such a large device, a homeowner thus must move the electrical device away from the wall socket until a line of sight is established. Furthermore, since most wall sockets for such devices are within 24 inches of the floor, the homeowner will typically have to lower himself to a possibly uncomfortable position to read the display on the face of the power meter.